1. Field
The present disclosure relates to a doped graphene, a method of manufacturing the doped graphene, and an electrode, a display device, and a solar cell including the doped graphene. The doped graphene may have excellent electrical characteristics.
2. Description of the Related Art
Generally, graphite has a structure in which two-dimensional (2D) graphene sheets, in which carbon atoms are connected to each other in a hexagonal array, are stacked on each other. Recently, several studies showed that single-layered or multiple-layered graphene sheets have amazing properties. One notable property is that electrons flow in a graphene sheet as if they are weightless, which means that electrons flow at the velocity of light in vacuum. In addition, an unusual half-integer quantum hall effect for both electrons and holes has been observed in graphene sheets.
Electron mobility in known graphene sheets is about 20,000 to about 50,000 square centimeters per volt per second (cm2/Vs). Also, it is advantageous to use graphene sheets because products made from graphite may be inexpensive, while products made from carbon nanotubes, which are similar to graphene sheets, may be expensive due to low yields obtained during the synthesis and purification of carbon nanotubes, even though the carbon nanotubes themselves are inexpensive. Single wall carbon nanotubes exhibit different metallic and semiconducting characteristics depending on their chirality and diameter. Thus, in order to obtain a metallic single wall carbon nanotube composition or a semiconducting single wall carbon nanotube composition, it is desirable to separate the single wall carbon nanotubes from each other in order to obtain desired metallic or semiconducting characteristics respectively. Furthermore, single wall carbon nanotubes having identical semiconducting characteristics may have different energy band gaps depending on their chirality and diameter. Thus, single wall carbon nanotubes are desirably separated from each other in order to obtain desired semiconducting or metallic characteristics. However, separating single wall carbon nanotubes is difficult.
On the other hand, because the metallic and semiconducting characteristics of a graphene sheet depend on crystallographic orientation, a device may be designed to exhibit desired electrical characteristics by arranging the crystallographic orientation of the graphene sheet in a desired direction. In addition, there is a need to control a work function of graphene in order to apply graphene having metallic features to electrodes of devices such as display devices or solar cells.